Thus, an undercarriage for a rotary wing aircraft is known that includes for example a tubular structure with skids. The tubular structure is designed to be mounted in the bottom portion of the aircraft. The tubular structure is generally fastened to a rigid structure that extends under the floor of the aircraft cabin.
Known tubular structures need to be capable of withstanding high levels of stress. During a vertical landing, the undercarriage needs to be capable of absorbing the kinetic energy of the aircraft making contact with the ground, without generating deformation in the structure of said aircraft.
In addition, the undercarriage is subjected to high levels of motion and/or loads, e.g. generated by the rotor of a helicopter.
Under no circumstances, the tubular structure must present physical properties that encourage a resonance phenomenon appearing on the ground, since that can damage the aircraft severely.
Known tubular structures are normally made of metal or composite material and present continuous tubular portions interconnecting the left and right halves of the undercarriage.
The connecting tubular portions generally pass through the bottom portion of the aircraft situated under the cabin.
Nevertheless, the tubular structures constituting known undercarriages, present a certain number of drawbacks.
Such tubular structures harm the aerodynamics of the aircraft and consequently lead to increased fuel consumption by the aircraft.
Furthermore, existing tubular structures have an unfavorable influence on the appearance of the aircraft while it is in flight.
It is also known with the help of document GB 942 294, an undercarriage for a rotary air wing aircraft. The undercarriage includes a tubular structure with skids, said tubular structure being designed to be mounted under or in a bottom portion of the aircraft. The tubular structure comprises left and right longitudinal portions that are retractable and comprise the skids. Each portion is suitable for moving between a retracted position in a cruising flight configuration and a deployed position in a landing configuration.